Recorder



y 3 R. P. DODDS 1,966,543

RECORDER Filed Oct. 28, 1930 Summer 83 I a Z M (Ittomegs in Fig.1;

Patented July 17, 1934 1 UNITED STATES nnconmm Robert P. Dodds, Troy, N.Y., assignor to W. & L. E. Gurley, Troy, N. Y., a corporation ofv NewYork Application October 28, 1930, Serial No. 491,758

' 9 Claims. (Cl. 2s4 1o) The present invention relates toclock-controlled recording mechanisms, and particularly to means forproviding a secondary time adjustment independent of the control of theclock escapement. It is desirable to provide for adjustment larger indegree than that afforded by the escapement. The best clock performancecan be secured by avoiding adjustment of the escapement once the clockhas assumed a definite rate.

The invention isparticularly intended for recorders of the graphic type,such, for example, as water stage recorders, and will be described asapplied to that type in which the pencil is caused to move by connectingit to the weight cord of the clock,

In devices of this character the rate of unwinding is controlled by theeffective radius of the drum, that is, the actual radius plus one-halfthe diameter of the cord. It follows that stretch,- ing of the cord suchas would reduce its diameter, wear of the cord, expansion of the drum,and similar variations, will all introduce errors in the movement of thepencil vover the record, no matter how accurately the clock itself mayfunction.

These difficulties are overcome by the structure described in theaccompanying drawing, in

' which,

Fig. 1 is a plan view of a water level recorder in which is embodied theadjustable drum;

Fig. 2 is a front elevation of the recorder shown Fig. 3 is an enlargedsectional view of the dru illustrating the manner in which it isattached to the clock or escapement-mechanism; and

Fig. 4 is a side view of thedrum. 1

In the drawing a cylinder 11 is mounted for rotation in a fixed standard12 and an adjustable support 10. The cylinder is adapted to hold arecord sheet having coordinate lines thereon and is rotated in eitherdirection by a perforated tape 13 cooperating with pins 14 on a pulley15 secured to the cylinder shaft. It is to be understood that one end ofthe tape is connected to a float and the other end to a weight, neitherof which is shown, since the actuation of the cylinder by these means iswell known in the art.

Mounted on guide rails 16 supported on standard 12 and support 10 andparallel with the axis of cylinder 11 is a pencil holder 1'7. A cord 18passes once around a grooved sheave 19 on the pencil holder and isconnected at its ends to a drum 21 and weight 22, respectively. Thesheave is normally clamped to the pencil holder so that the cord bindswith respect thereto, but may be loosened by unscrewing a clamp screw'20 to permit adjustment of the pencil holder with respect to the cord.A clock 23, including an escapement mechanism, permits uniform and timedunwinding of the cord from the drum, the 00 pencil, being normally fixedto the cord, moving longitudinally along the cylinder 11 as the cordunwinds. The mechanism above described conforms in a general way toknown practice in the recorder art. The invention is applicable to vari-66 ous recorders provided they be of the type in which the motion of therecording stylus is controlled by the winding or unwinding of a cord onor from a drum driven at uniform angular veloc ity. The usual way ofdriving such a drum at I0 uniform angular velocity is to connect it witha clock. Consequently, the above description is to be considered asillustrative rather than limiting.

The drum on which the pencil actuating cord is Wound comprises a splitcollar 24 cooperating with a tapered core 25 and having a helical groove26 therearound. Core 25 is connected by spokes 27 to a threaded hub 28secured to the clock shaft 29 by means of pin 31 or other suitablefastening means. It will be seen that the shaft 29 is journaled in abracket 32 on the instrument frame and that the clock is. fixed theretoby means of a retractible pin 33 on the bracket cooperating with adetent 34 in the clock housing. Rotation of shaft 29 is effected byweight 22, 86 controlled, of course, by the clock escapement, and turnsdrum 21'on its axis to permit unwinding of cord 18. 1

To modify the diameter of sleeve 24 a flanged nut 35, also split, isthreaded on hub 28.v This nut bears against the split sleeve and,depending on whether it is screwed toward or from the tapered core,positions the split sleeve with respect to core 25 thereby to expand orcontract the sleeve. Nut 35 is provided with projections 36 adjacent thesplit 37, one of the projections having a threaded aperture 38 toaccommodate a capstan screw 39, the head of which bears against theopposite projection. Access may be had to screw 39 through an opening 41in the flange of thenut. By turning screw 39 the nut may be loosened topermit turning of the nut and axial adjustment of the split sleeve 34,but when the projections 36 are drawn toward each other by the screw,the nut is locked to the hub. It is thus possible to maintain theadjusted relation of the split sleeve and core as long as the instrumentfunctions accurately.

In operation, the clock is rotated counterclockwise to wind the cord onthe drum, the pin 33 first sleeve.

being disengaged to permit rotation of the clock, and then reengaged.The clamp screw 20 is then partially unscrewed, the pencil is set to thecorrect time marking, and the clamp screw 20 again set up. The clockpermits uniform unwinding of the cord as weight 22 tends to unwind itfrom the drum. The rate at which the pencil moves is dependent on thediameter of the drum. This diameter is adjustable to permit adjustmentof the rate of movement of the pencil with respect to the record sheetWithout requiring adjustment of the time rate of the clock.

The efiect is to minimize all necessity for adjustment of the clockescapement, and to provide a precise adjustment of considerable range,permitting neutralization of errors without interference with the clockmechanism. V

While the preferred embodiment of the invention has been described inconsiderable detail, it is to be understood that the invention isapplicable to other recording instruments, and that various structuralchanges fall within the scope of the invention.

In the claims the word stylus will be used as a generic term to coverthe pencil described in the specification, and other equivalent markingdevices.

What is claimed is:-

1. In a recording instrument, a clock; a rdtatable drum controlled bysaid clock; a cord wound on said drum; recording means actuated bymovement of the cord upon rotation of the drum: and adjusting means forvarying the diameter of the drum.

2. In a recording instrument, a clock; a rotatable expansible drumcontrolled by said clock; a cord wound on said drum; recording meansactuated by movement of the cord upon rotation of the drum; andadjusting means for expanding said drum to vary the circumferencethereof.

3. In a recording instrument, a clock; a tapered core; a split sleeveencircling said core; means for rotating said core including a cordwound on said sleeve, the rotation of said core being controlled by saidclock; recording means actuated by the cord as it unwinds from thesleeve; and means for positioning the sleeve with respect to the core tovary the diameter of the 4. In a recording instrument, a clock; atapered core; a split sleeve encircling said core;

' means for rotating said core including a cord wound on. said sleeve,the rotation of said core for positioning said sleeve with respect tosaid core to vary the diameter of the sleeve.

5. In a recording instrument, a clock; a. tapered core having a threadedhub; a split sleeve encircling said core; means for rotating said coreincluding a cord Wound on said sleeve, the rotation of said core beingcontrolled by said clock; recording means including a record sheet and amarking stylus; said cord being wound on said sleeve and adapted to movesaid stylus with respect to said sheet While being unwound from thesleeve; and means cooperating with said threaded hub for positioningsaid sleeve with respect to said core to vary the diameter of thesleeve.

6. In a recording instrument, a clock; a tapered core; a split sleeveencircling said core; means for rotating said core including a cordwound on said sleeve, the rotation of said core being controlled by saidclock; recording means actuated by the cord as it unwinds from thesleeve; means for positioning said sleeve with respect to the-core tovary the diameter of the sleeve; and means 'for locking said positioningmeans with respect to said core.

'7. In a recording instrument, a clock; a tapered core having a threadedhub controlled by said clock; a split sleeve encircling said core;

eans for rotating said core including a cord Wound on said sleeve, therotation of saidcore being controlled by said clock; recording meanseluding a record sheet and a marking stylus, said cord being wound onsaid sleeve and adapt-- ed to move said stylus with respect to saidsheet while being unwound from the sleeve; and a flanged nut cooperatingwith said threaded hub and said sleeve for positioning the sleeve withrespect to said core to vary the diameter of the sleeve. 7 H

8. In a recording instrument, a clock; a tapered core having a threadedhub controlled by said clock; a split sleeve encircling said core; meansfor rotating said core including a cord wound onsaid sleeve, therotation of said core being controlled bysaid clock; recording meansincluding a record sheet and a marking stylus,

said'cord being wound on said sleeve and adapted to move said styluswith respect to said sheet While being unwound from the sleeve; a splitnut cooperating with said threaded hub and said sleevefor positioningthesleeve with respect to 9. The combination of claim 1,.furthercharacterized in that said drum is spirally grooved and said cord iswound spirally in said groove.

- ROBERT PI DODDS.

